JP2017071950A - Seed germination-promoting method, and stabilization method for slope surface layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stabilization method for a slope surface layer that inhibits collapsing due to freezing and thawing, and a seed germination-promoting method for promoting germination of mixed seeds.SOLUTION: Plant seeds 4 are added and agitated in a cotton-like raw bamboo fiber formed by compressing and pulverizing a raw bamboo tree using a double shaft compression pulverizer, for making a cushioning material free of an adhesive and holding the seeds 4 dispersed rotatably in an entangled cotton-like raw bamboo fiber body. The seeds are planted on a ground surface by installing the cushioning material on the ground surface. The seeds are held rotatably and movably in the entangled cotton-like raw bamboo fiber body, thereby preventing delay or inhibition of germination of the seeds. Flexibility of the cotton-like raw bamboo fiber is maintained over a long period, without being hardly affected by freezing and thawing or deterioration caused by ultraviolet rays.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a germination promoting method for promoting germination of seeds sown in slope greening and the like, and a method for stabilizing a slope surface using the seed germination promotion method.

  Conventionally, as a technique of slope greening, the material that is crushed bamboo until it becomes cottony is sprayed on the slope to promote the growth of nitrogen-fixing bacteria on the slope and to grow green plants without using chemical fertilizer A slope planting technique that is favorable over a long period of time is known (Patent Document 1). In this slope greening technology, a vegetation base material containing cotton-like bamboo fibers formed by crushing bamboo until the proportion of crushed particles or fibers passing through a 1 mm mesh with sieve classification reaches 60% by weight or more The vegetation basement layer is formed by spraying the surface of the vegetation, and the vegetation basement layer is allowed to stand naturally, and nitrogen-fixing bacteria are propagated in the vegetation basement layer to fix nitrogen in the air. The plant is grown with nitrogen fertilizer as an ingredient.

  When actually planting using cotton-like bamboo fiber as described above, the vegetation base layer sprayed on the slope is bonded to cotton-like bamboo fiber to prevent it from flowing out due to rain or wind. It is common to use a method of fixing by mixing and spraying the agent.

JP 2010-70963 A

Nagasawa Tetsuaki and Umeda Yuji, “Effect of Freezing and Thawing on the Water Corrosion Resistance of Soil”, Proceedings of Agricultural Civil Engineering Society, 1981 (94), pp.48-54.

  However, when a vegetation base layer was actually sprayed with a mixture of cotton-like bamboo fibers and sprayed, the adhesive deteriorated in a relatively short period of time in Takayama and cold regions, and the vegetation base layer became relatively short. There was a phenomenon of collapse in the meantime. This is because when the ground temperature drops below freezing with the vegetation basement layer containing water due to rainfall or snowfall, the solidified adhesive cracks due to volume expansion accompanying freezing of the water, and the melting of the ice causes water to break into the cracks. It is thought that this is due to a so-called freeze-thaw action, in which disintegration is promoted by repeating the cycle of invasion. This freezing and thawing action is known as one of the periglacial actions (soli fraction, etc.) that promote the crushing of rocks in the alpine zone. In cold region agriculture, the problem of erosion of slope soil due to the same phenomenon has been reported (for example, Non-Patent Document 1). Further, the adhesive has a property of being deteriorated by ultraviolet rays. Therefore, after several months have passed, the adhesive on the sprayed slope is deteriorated by ultraviolet rays and collapses into a granular shape. Once the solidified adhesive is broken, the vegetation base layer becomes a crushed grain, easily eroded by rainfall and wind, and the vegetation base layer collapses in a relatively short period of time.

  FIG. 21 is a photograph of an actual spraying site by a conventional spraying method (a method of spraying an adhesive mixed with cotton-like bamboo fiber). As can be seen from the photograph, the surface layer of the vegetation base layer sprayed by freezing and thawing cycles and UV deterioration collapses and peels off, and the internal wire mesh is exposed (FIG. 21A). In addition, as shown in FIGS. 21B and 21C, it can be seen that a vegetation base that has collapsed and becomes granular is deposited in the lower part of the slope.

  In addition, when seeds of plants are mixed with cotton-like bamboo fibers and sprayed on the slope to form a vegetation base layer containing seeds, the seeds are fixed by solidifying the adhesive. There is also a problem that seeds are less likely to germinate due to fixation.

  Therefore, the object of the present invention is to stabilize the slope surface layer in which when the vegetation base layer using cotton-like bamboo fibers as a vegetation base is formed on the slope, the vegetation base layer is less likely to collapse due to freeze-thaw action. It is an object of the present invention to provide a seed germination promotion method that makes it easy to germinate mixed seeds when seeds are mixed in a vegetation base layer.

  In the seed germination promotion method according to the present invention, the seeds are added to the cotton-like raw bamboo fibers formed by compressing and pulverizing raw bamboo shoots with a biaxial compression pulverizer, and the seeds are stirred. In a freely rotatable state, a cushion material that does not contain an adhesive dispersed and supported in the entangled body of the cotton-like raw bamboo fiber is generated, and the seed is grounded by laying the cushion material on the ground surface. It is characterized by planting.

  According to this configuration, by laying a cushion material of cotton-like raw bamboo fiber that does not contain an adhesive on the ground surface, the seed mixed with the cotton-like raw bamboo fiber is rotated and entangled in the cotton-like raw bamboo fiber entanglement. It is carried in a state where movement is not hindered. By setting the seeds in a state in which rotation and movement are not hindered in this way, seed germination is prevented from being delayed or inhibited. In addition, when fixed with an adhesive as in the conventional construction method, the function of bamboo fiber is lost, and the adhesive deteriorates due to ultraviolet rays, and also collapses in about 2 to 3 months, but the cushion laid on the ground surface in the present invention Since the material is held only by the entanglement of the raw bamboo fiber, the flexibility of the cotton-like raw bamboo fiber is maintained for a long period of time, and the influence of deterioration due to ultraviolet rays is hardly observed.

  In the present invention, raw bamboo is used as a material for bamboo fiber. Bamboo bamboo refers to bamboo in a state before logging and before drying, and before the skin becomes brown and dried (dead bamboo). When withered bamboo is used, the structure is hard, and when it is pulverized, it does not become a sufficient fiber, and most of it becomes powder. Further, the flexibility of the fiber is poor, and the entangled state is not sufficient. On the other hand, when raw bamboo is used as a material, each single fiber is rich in flexibility and has a longer length than withered bamboo, so that cotton fibers are sufficiently intertwined with each other. Moreover, even if time passes after making it into cotton-like raw bamboo fiber once, a softness | flexibility is maintained.

The method of stabilizing the slope surface layer according to the present invention comprises adding seeds of plants to cotton-like raw bamboo fibers formed by compressing and crushing raw bamboo shoots with a biaxial compression pulverizer, and stirring the seeds. However, in a freely rotatable state, a cushion material that does not include an adhesive is dispersed and supported in the entangled body of the cotton-like raw bamboo fiber,
A cushion layer is formed by spraying the cushion material onto a natural ground surface on a slope, thereby covering the natural ground surface.

  According to this structure, germination of seeds is promoted as described above by laying the cushion material of cotton-like raw bamboo fiber not containing an adhesive on the ground surface. In addition, since the cushion layer is made of bamboo fiber made from raw bamboo and does not contain an adhesive, even if it is melted after freezing in a moisture-containing state, it is restored by the elasticity of the fiber, and the freeze-thaw action is extremely high. It is hard to receive. Moreover, since the fibers are in an intertwined state, they are not easily blown even in strong winds, and the cushion layer covering the ground surface is maintained. As a result, even in high mountains and cold regions, it is possible to maintain a state where it is difficult to be eroded over a period until the plant grows, and to stabilize the slope surface layer.

  In the method for stabilizing a slope surface layer according to the present invention, the seed of the plant may be a seed of a grass family or a legume plant.

  Leguminous plants germinate and grow even under relatively adverse conditions, and after growth, nitrogen fixation by rhizobia is performed, promoting the establishment of other plants.

In the method for stabilizing the slope surface layer according to the present invention, the cotton-like raw bamboo fiber having a bulk specific gravity of 0.1 to 0.3 g / cm ³ can be used.

  Moreover, in the stabilization method of the slope surface layer which concerns on this invention, the said cushion layer shall be formed in thickness of 0.5-150 mm on the natural ground surface of a slope.

  According to the present invention, seeds are dispersed and supported in the entangled body of cotton-like raw bamboo fiber, and fixed with an adhesive by maintaining a state in which the seeds can move freely without being fixed with an adhesive. Compared to the case, the germination rate is increased and the germination rate is also increased. In addition, the entangled body of cotton-like raw bamboo fiber is an intertwined fiber, so when sprayed on the slope and laid as a vegetation base layer, it can be stably fixed to the slope without collapsing from the slope. . Moreover, since it is not what is fixed with an adhesive agent, the problem of the collapse | disintegration by ultraviolet degradation of an adhesive agent does not arise. In addition, due to the flexibility of cotton-like bamboo fiber, there is no phenomenon such as splitting and collapsing due to freezing and thawing even in places where freezing and thawing are repeated. The layer can be stably provided on the slope.

It is a comparison photograph of cotton-like raw bamboo fiber (left) produced from raw bamboo and cotton-like dead bamboo fiber produced from dead bamboo (right). It is an electron micrograph of the cotton-like raw bamboo fiber which forms the cushion layer in a present Example. It is an electron micrograph of the cotton-like raw bamboo fiber which mixed the adhesive agent which produces the conventional vegetation base layer. It is a schematic diagram showing the structure of the slope surface layer formed by the stabilization method of the slope surface layer which concerns on this invention. It is a figure which shows the mode of a spray budding test. It is a figure which shows the change of the number of budding and survival of each test division counted in each observation day in a spray germination test. It is a figure which shows the measurement result of the moisture content in the soil of each test section measured simultaneously in the test of FIG. It is a figure showing the result of the wicking water absorption test of the vegetation base layer of the cotton-like raw bamboo fiber using an adhesive agent, and the vegetation base layer of the cotton-like raw bamboo fiber which does not contain an adhesive agent. It is the figure which showed typically the relationship between the compressive stress obtained by a test, and compressive strain. It is a figure which shows the relationship between the compressive stress and the compressive strain which were obtained from the uniaxial compression test of the bamboo fiber base material. (Test results with high water content immediately after spraying) It is a figure which shows the relationship between the compressive stress and the compressive strain which were obtained from the uniaxial compression test of the bamboo fiber base material. (Test results in a state where 53 days have elapsed after spraying and the specimen has been dried) It is a figure which shows the relationship between the compressive stress and the compressive strain which were obtained from the uniaxial compression test of the bamboo fiber base material. (Test results for specimens that were frozen and thawed at a medium moisture content) It is a figure which shows the relationship between uniaxial compressive strength and a water content ratio in FIG. It is an external view of a aggregate analysis apparatus. It is a figure which shows the result of the aggregate analysis test of the specimen before dispersion | distribution about dry bamboo fiber. It is a figure which shows the result of the aggregate analysis test of the specimen before dispersion | distribution about the dried bamboo fiber after freezing and thawing | decompression. It is a figure explaining the test method in a seed fixed germination test. It is a progress photograph which shows the mode of the change at the time of seed germination of the seed fixation test group and a seed free test group in a seed fixed germination test. It is a figure which shows the time change of the germination rate of each test section. It is a progress photograph showing the movement of the seed at the time of germination. It is the photograph of the actual spraying field by the conventional spraying method (construction method which mixes and sprays an adhesive agent to cotton-like bamboo fiber).

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(1) Vegetation base material to be used The cotton-like raw bamboo fiber used as a vegetation base material in this example is formed by compressing and grinding raw bamboo cocoons with a biaxial compression pulverizer. In compression pulverization, as in Patent Document 1, the bamboo material is compressed and crushed by passing the bamboo material between two screws of a twin screw extruder that meshes or rotates in close proximity, and at the end of both screws. By extruding the compressed and crushed bamboo material between the teeth of the fixed teeth provided, and cutting the compressed and crushed bamboo material extruded by a rotating blade in contact with the tooth plate surface of the fixed teeth, into a cotton shape It is made into fiber. In this way, by compressing and crushing with a twin screw extruder, and further cutting with a fixed tooth and a rotating blade, the bamboo material is finely crushed and the cell walls of the fiber cells are destroyed, causing the growth of bacteria and filamentous fungi It will be in a state suitable for.

  Moreover, as a bamboo material to be used, raw bamboo is used instead of withered bamboo. “Raw bamboo” refers to bamboo that has just been cut and has not yet turned brown after drying and hardening. Bamboo hardens and becomes brittle when it dies. Therefore, when dead bamboo is compressed and pulverized by a biaxial compression pulverizer, it collapses into a powder and sufficient flexibility cannot be obtained. On the other hand, raw bamboo before curing has high fiber flexibility, and when this is compressed and pulverized by a biaxial compression pulverizer, it becomes a flexible cotton-like fiber. Once made into a cotton-like fiber, the flexibility is maintained even after drying with time, and it becomes difficult to harden or disintegrate into powder.

  FIG. 1 is a comparative photograph of cotton-like raw bamboo fibers (left) produced from raw bamboo and cotton-like dried bamboo fibers (right) produced from dead bamboo. The left and right cotton-like bamboo fibers in FIG. 1 were produced using the same pulverizer under the same conditions. The left cotton-like raw bamboo fiber was cut from raw bamboo within 30 days, and the right cotton-like dead bamboo fiber was dead bamboo that had been cut for more than 180 days. The cotton-like raw bamboo fiber on the left is long and has a fluffy nature with a lot of air inside, and each fiber is intricately entangled and difficult to disperse. On the other hand, the cotton-like bamboo fiber on the right side is often pulverized until each fiber is short and powdery. Since each of the fibers is short, it becomes close to a powder form, lacks flexibility, and the degree of entanglement of each fiber is small and easily blown by the wind.

In addition, when the bulk specific gravity of the bamboo fiber produced | generated from raw bamboo was actually measured, it was 0.1-0.3 g / cm < ³ >.

(2) Cushion layer In the present invention, the cushion layer is made of cotton-like raw bamboo fibers in a state where the seeds are rotatable by adding and stirring the plant seeds to cotton-like raw bamboo fibers not containing an adhesive. It is formed so as to be dispersed and supported in the entangled body. FIG. 2 is an electron micrograph of the cotton-like raw bamboo fiber forming the cushion layer in this example, and FIG. 3 is an electron micrograph of the cotton-like raw bamboo fiber mixed with an adhesive that forms a conventional vegetation base layer. is there. 2 and 3 were taken using an electron microscope (SEM). In FIG. 2, the magnification of each photograph is 200 times for (a), 1000 times for (b), 900 times for (c), and 2000 times for (b). In FIG. 3, the magnification of each photograph is 150 times for (a), 1000 times for (b), 1000 times for (c), and 3000 times for (b). The samples shown in FIGS. 2 and 3 are actually taken and taken by a sprayer as a test. As the adhesive resin, Loan Fix (trade name: manufactured by Showa Denko KK), which has good wettability with bamboo fibers, was used.

  In the cotton-like raw bamboo fiber mixed with the adhesive that generates the conventional vegetation base layer, it is observed that the resin is entangled in a film shape between the fibers and the fibers are fixed with the resin. Further, as shown in FIG. 3D, the surface of each fiber is coated with an adhesive. On the other hand, as for the cotton-like raw bamboo fiber which forms the cushion layer of this invention, one piece of bamboo fiber is seen.

  As shown in FIG. 3, bamboo fiber coated with an adhesive is highly resistant to degradation by bacteria and the like and can be expected to have a long life, but on the other hand, water permeability is considered to decrease.

(3) Construction method When the cushion layer is constructed on the slope, the above-described cotton-like raw bamboo fiber mixed with plant seeds is sprayed onto the slope with a spraying machine. The spraying method using a spraying machine is the same as that generally performed widely. The thickness of the cushion layer is appropriately adjusted according to the situation at the site (inclination angle of the slope, sunshine conditions, rainfall conditions), but generally it is preferably about 0.5 to 150 mm. As the plant seed, a plant belonging to the family Gramineae (Yoshiba, Enokorogusa, Ushikokegusa, etc.) or Legumes (White clover, Yakuzu Pea, Miyakogusa, etc.) can be used. FIG. 4 is a schematic view showing the structure of a slope surface layer formed by the method for stabilizing a slope surface layer according to the present invention. In the slope surface structure 1 of the present invention, the seed 4 is prevented from rotating and moving by adding and stirring the plant seed 4 to the cotton-like raw bamboo fiber on the surface of the natural mountain 2 forming the slope. The cushion layer 3 is formed by spraying a cushion material that does not contain an adhesive dispersed and supported in the entangled body of the cotton-like raw bamboo fiber without any contact. Here, the “state in which rotation and movement are not hindered” refers to a state in which the movement is not hindered when the seed moves (see FIG. 20) during germination of the seed.

(4) Spray germination test Next, the spray germination test by the seed germination promotion method of the present invention was performed using the above-described cottony raw bamboo fiber, and the results will be described.

(4.1) Test method In the spraying and budding test, as in FIG. 4, cotton-like raw bamboo fibers mixed with seeds were sprayed on the surface of the soil filled in the bottom of the cultivation container to form a test plot. It was formed by observing the number of seed emergence by placing it in the field. The number of seeds to be mixed was set to be the same in each test section, and the sunlight conditions and the like were set to the same conditions. As plant seeds, grass (Kentucky bluegrass) was used as a gramineous plant, and white clover seeds were used as legumes. Moreover, in order to compare and verify the effects of the present invention, the following blends (a) to (f) were used as spray materials sprayed on the test section. As an adhesive, Loan Fix (trade name: manufactured by Showa Denko KK) was used. Three test sections were prepared for each adhesive addition amount and various child types. Irrigation was not performed artificially, but only by natural rainfall. The number of budding and surviving plants was counted and recorded for each elapsed day. In counting on each observation day, dead individuals were excluded.

(A) Bamboo fiber 99.5 wt%, adhesive 0.5 wt%, Yashiba seed mixed (b) Bamboo fiber 99.5 wt%, adhesive 0.5 wt%, legume seed mixed (c) Bamboo fiber 99. 0 wt%, adhesive 1.0 wt%, Yashiba seed mixed (d) bamboo fiber 99.0 wt%, adhesive 1.0 wt%, legume seed mixed (e) bamboo fiber 100.0 wt%, adhesive 0. 0wt%, mixed with turf seeds (f) 100.0wt% bamboo fiber, 0.0wt% adhesive, mixed with legume seeds

(4.2) Test results Table 1 shows the number of budding and survival in each test section counted on each observation day. FIG. 6 shows the change in the number of budding and survival in each test group counted on each observation day. In addition, the value of the germination / survival number shown in Table 1 and FIG. 5 is the average number of the three test sections of the same seed type and the same adhesive addition amount. The test plots formed by the germination promotion method according to the present invention are (e) and (f). (A)-(d) is a test section formed by spraying cotton-like bamboo fibers mixed with an adhesive as usual.

  As a result of the test, in the leguminous plant, in the test section (f) related to the present invention, the average was 91.7 on the seventh day, the average 132.0 on the 14th day, the average 108.7 on the 28th day, 49 An average of 81.3 germinations were observed on the day. The reason why the number of germinated seeds decreased after the 28th day is that the container was of a limited size, and the germinated seedlings and those that grew early died. On the other hand, in the test plot by the conventional method, the test plot (b) germinates earliestly, averaging 27.7 on the 14th day, average 55.7 on the 28th day, and average 34.0 on the 49th day. Germination was observed. The test plot (d) was the latest, with an average of 0.7 germinations observed on the 28th day and an average of 3.0 germinations on the 49th day.

  In Yoshiba, germination of an average of 0.3 on the 14th day, an average of 112.0 on the 28th day, and an average of 80.0 on the 49th day was observed in the test plot (e) related to the present invention. It was. On the other hand, in the test plot according to the conventional method, germination of 6.0 on average on the 28th day and 33.0 average on the 49th day was observed in the test plot (a). In the test plot (c), an average of 12.7 germinations were observed on the 49th day.

  From the above results, when compared with seeds of the same species, the germination rate of the seeds in the test plots (e) and (f) according to the present invention was significantly accelerated compared to other test plots according to the conventional method. The effect of promoting the germination rate of seeds by the seed germination promotion method of the invention was confirmed.

  FIG. 7 is a diagram showing the measurement results of the moisture content in the soil of each test section measured simultaneously in the test of FIG. From FIG. 7, regarding the moisture content in the soil in each test section, the moisture contents of the test sections (e) and (f) are the water contents of the test sections (a) and (b) and the test sections (c) and (d). Although it was slightly larger than the amount, there was not much difference. From this, it is considered that the influence of the difference in soil water content is small for the above result that the seed germination rate in the test plot relating to the present invention is high. A large difference between the test sections (a) to (d) and the test sections (e) and (f) is the presence or absence of an adhesive. In the test plots (a) to (d), the seeds are fixed by an adhesive, whereas in the test plots (e) and (f), the seeds are prevented from rotating and moving in the fluffy bamboo fiber. It is speculated that this difference is greatly involved in the promotion of seed germination.

(5) Comparison of water content Next, quantitative comparison of water retention between the vegetation base layer of cottony raw bamboo fiber using a conventional adhesive and the vegetation base layer used in the germination promotion method according to the present invention is quantitative. The results will be described.

  FIG. 8 is a diagram showing the results of a water absorption test of a vegetation base layer of cotton-like raw bamboo fiber using an adhesive and a vegetation base layer of cotton-like raw bamboo fiber that does not contain an adhesive. In the experiment, first, the material constituting the vegetation base layer was filled into a cylindrical container having an inner diameter of 40 mm and a height of 10 mm to prepare a sample. First, the dry weight of each sample was measured, and then, as shown in FIG. 8A, each sample was placed upright in a tray filled with water so that the lower end was immersed below the water surface. During water absorption, water was constantly replenished so that the tray was always full so that the water level in the tray did not change. After allowing the sample to stand for about 24 hours and sufficiently absorb water, each sample was taken out and cut into pieces every 2.5 cm in the axial direction, and the mass of each part (each sample section in FIG. 8A) was measured. . From the measurement result of mass, the water content ratio in each sample section was obtained by the following equation.

  The measurement results are shown in FIG. The dry mass of each sample was 16.6 g of the vegetation base layer A of the cotton-like raw bamboo fiber to which the adhesive was added, and 15.6 g of the vegetation base layer B of the cotton-like raw bamboo fiber not containing the adhesive. As a result of the experiment, the vegetation base layer A was pumped up to a sample section of 8.75 cm, and the vegetation base layer B was pumped up to a sample section of 11.25 cm. In each sample section, the vegetation base layer B had a water content of about 90 mass% on average in comparison with the vegetation base layer A. From this, it can be seen that the vegetation base layer B to which no adhesive is added has a higher water retention capacity than the vegetation base layer A to which the adhesive is added, and also has a higher pumping power to suck up water at the bottom by capillary action.

(6) Deformation / strength test (6.1) What is a uniaxial compression test? A uniaxial compression test is usually performed to obtain the shear strength of soil. FIG. 9 schematically shows the relationship between compressive stress and compressive strain obtained in the test. The compressive stress of undisturbed soil shows a peak value at a certain compressive strain, and this value is the uniaxial compressive strength. On the other hand, in the case of ground clay, the compressive stress increases monotonously and does not show a peak value. Therefore, in such a case, the compressive stress when the compressive strain reaches 15% is regarded as uniaxial compressive strength.

(6.2) Test method Two types of bamboo fiber mixed with water (with and without adhesive) are sprayed onto a cylindrical container with an inner diameter of 3.5 cm and a height of 7 cm, the frame of the cylindrical container is removed, and a uniaxial compression test is performed. A sample was prepared. These samples were left in the air for different periods (0, 10, 56 days) to change the degree of drying. Further, in order to examine the influence of freezing / thawing, moisture was added to the sample that had been dried (left for 53 days) by spraying, and it was frozen / thawed. A uniaxial compression test was performed using the sample thus prepared. The test was performed in triplicate using three specimens for one type of sample.

(6.3) Test Results FIGS. 10 to 12 show the relationship between the compressive stress and the compressive strain obtained from the uniaxial compression test of the bamboo fiber base material. FIG. 10 shows a test result at a high water content ratio immediately after spraying, FIG. 11 shows a test result in a state where 53 days have passed after spraying and drying of the specimen has progressed, and FIG. 12 shows freezing / thawing in a medium water content state. It is a test result about the test piece which gave.

  Regardless of whether or not the adhesive was added, the degree of water content, and whether or not freezing / thawing was performed, the compressive stress did not show a peak, and the specimen did not break. This indicates that the toughness (proper property that is not easily broken) and spreadability (property that can be deformed without breaking) of the bamboo fiber base material are maintained even after addition of adhesive, freezing and thawing. . The toughness and spreadability of bamboo fiber is due to the fact that the single bamboo fiber has a high tensile strength (it is difficult to break even when compressed), and the tensile strength is further increased by entanglement.

  Regarding the uniaxial compressive strength of each specimen, the compressive stress when the compressive strain reached 15% was considered to correspond to the uniaxial compressive strength. FIG. 13 shows the relationship between the uniaxial compressive strength thus obtained and the water content ratio. The figure also shows the number of days that have elapsed since the specimen was created by spraying. The moisture content immediately after spraying (0 day) was 265 to 272 wt% in the case of the adhesive-added specimen and 319 to 330 wt% in the case of the adhesive-free specimen. It is considered that the water content ratio was decreased by the addition of the adhesive because the density of the adhesive was higher than that of the bamboo fiber and because of the water repellent effect of the adhesive. The uniaxial compressive strength immediately after spraying was 11 to 15 kPa in the case of the adhesive-free specimen, and 8 to 9 kPa in the case of the adhesive-added specimen. When 10 days passed after spraying, the water content ratio in the case of the specimen without additive was decreased to 269 to 272 wt%, and the uniaxial compressive strength was increased to 14 to 19 kPa accordingly. On the other hand, the uniaxial compressive strength hardly changed although the moisture content of the adhesive-added specimen decreased to 179 wt%. When 56 days passed after spraying, the water content ratios of the adhesive-free specimen and the adhesive-added specimen decreased to 19 to 32 wt% and 21 to 26 wt%, respectively, and there was almost no difference between the two. On the other hand, the uniaxial compressive strength showed a larger value in the specimen without an adhesive than in the specimen with an adhesive.

  From the above results, when the uniaxial compressive strength of the bamboo fiber base material with and without the adhesive is compared at the time when the same number of days have passed after spraying, it is clear that the equipment with the adhesive added shows a low value. It was.

  Next, the effect of freezing / thawing on uniaxial compressive strength will be described. The specimens are created as follows. First, the dried specimen that had passed 56 days after spraying was sprayed with water to make it wet, and then the specimen was frozen and then naturally thawed. The water content ratio of the specimens was 148 to 176 wt% for the specimens without an adhesive and 93 to 103 wt% for the specimens with an adhesive. Moreover, the uniaxial compressive strength was 23-29 kPa and 16-21 kPa, respectively. These data are located on the correlation curve in both cases of no addition of adhesive and addition of adhesive. This indicates that freezing / thawing does not cause a decrease in the uniaxial compressive strength of bamboo fiber equipment.

(7) Evaluation of erodibility by aggregate analysis test (7.1) What is aggregate? Soil is composed of particles of various sizes such as clay, silt and sand. When each particle exists alone, it is called a primary particle. Usually, sand exists as primary particles, but primary particles of clay and silt aggregate to form secondary particles (aggregates). For the formation of aggregates, oxides such as iron, aluminum and silicon for binding primary particles play an important role.

(7.2) Calculation of the size of aggregates When air-dried soil is put into water, the binding stress between aggregates is lost due to fluorination (slacking), and aggregates collapse due to the force of interstitial air. When an external force is applied to this, the aggregate becomes smaller, but eventually settles to a certain size. Such stable aggregates are called water-resistant aggregates. In order to apply an external force, a nodule analyzer is used, and the size of the nodule is calculated based on the result of the nodule analysis test.

(7.3) Relationship between aggregates and erosion Aggregates are related to the stability of soil structure and the size and shape of gaps, and affect the water retention, water permeability and air permeability of soil. Since the soil in which aggregates are developed is excellent in water permeability and air permeability, the amount of water flowing on the soil surface is reduced, and soil erosion is suppressed. Therefore, the result of aggregate analysis can be used as an index of soil erosion.

(7.4) Bamboo fiber is regarded as soil Bamboo fiber is not soil, but the sprayed base (cushion layer) of bamboo fiber is regarded as soil, and the aggregate size (aggregate) of bamboo fibers is aggregated analysis test Calculated by Hereinafter, the term “aggregate” is used for bamboo fiber.

(7.5) Method of aggregate analysis test FIG. 14 shows an aggregate analysis apparatus. The lower part of the device consists of a water tank (diameter 190 mm, depth 370 mm) and a combination screen. The size of the mesh sieve is 2.0, 1.0, 0.5, 0.25, 0.1 mm from the top. The test method is as follows.
(I) Fill the water tank with water and assemble five sieves in the water in the water tank. This is to prevent air from entering between the sieves.
(Ii) About 20 g of bamboo fiber sample is spread thinly on the top sieve (2.0 mm) and left for 1 day.
(Iii) The sample is sieved by moving the arm up and down 32 times per minute for 3 hours with a stroke of 3.8 cm.
(Iv) Collect the sample remaining on each sieve, oven dry at 110 ° C., and measure its mass.

(7.6) Sample type and adjustment As a bamboo fiber sample for aggregate analysis, a cylindrical specimen for a uniaxial compression test prepared by spraying was used. The following two types of specimens were used for aggregate analysis:
(A) An air-dried cylindrical specimen prepared by spraying.
(B) A wet cylindrical specimen was frozen and thawed and then air-dried.
Samples (a) and (b) above were crushed, and samples used as they were for each sample (specimen before dispersion) and samples dispersed in water (specimen after dispersion) were prepared. The specimen before dispersion consists of an aggregate of large bamboo fibers. The aggregate is thought to be maintained by the entanglement of bamboo fibers. On the other hand, the specimen after dispersion was prepared by putting a sample in a bottle filled with water and giving an impact by shaking for 30 minutes. Bamboo fiber aggregates are discrete and small.
Aggregate analysis was performed on the specimen prepared before and after dispersion in the manner described in (6.5).

(7.7) Results of Aggregate Analysis Test FIG. 15 shows the results of the aggregate analysis test of the specimens before and after dispersion on the dried bamboo fiber. The horizontal axis represents the size (particle size) of the aggregate. The particle size (0.1, 0.25, 0.5, 1.0, 2.0 mm) of the plotted points is the size of the sieve mesh. 0.1 is a particle size of 0.1 mm or more and less than 0.25 mm, 0.25 is a particle size of 0.25 mm or more and less than 1.0 mm, 1.0 is a particle size of 1.0 mm or more and less than 2.0 mm, 2 0.0 corresponds to a particle size of 2.0 mm or more. The vertical axis represents the residual rate of the sample remaining on the sieve, and was obtained by dividing the mass of the specimen remaining on each sieve by the total mass.

  In FIG. 15, in the case where no adhesive is added, an aggregate having a particle size of 2.0 mm (size of 2.0 mm or more) accounts for 96 wt% before dispersion, and there are almost no aggregates smaller than that. There wasn't. However, the residual ratio of the aggregate having a particle size of 2.0 mm was greatly reduced from 96 wt% to 44 wt% by shaking the specimen and applying the dispersion treatment. On the other hand, the residual ratio of aggregates having particle sizes of 1.0, 0.5, 0.25, and 0.1 mm was 0 wt% before the dispersion treatment, but increased to 10-15 wt% after the dispersion treatment. did. This means that the large aggregate collapsed by shaking and turned into a small aggregate. Considering this in relation to rainwater erosion of the bamboo fiber spray base, when the rainwater impacts the base, the bamboo fiber aggregate collapses into a small aggregate and the base is susceptible to erosion.

  In the case of addition of an adhesive, as in the case of no addition, the residual ratio of the aggregate having a particle size of 2.0 mm is greatly reduced from 95 wt% before dispersion to 38 wt% after dispersion, and is 1.0 mm or less. The aggregate of the particle size increased from 0 wt% before dispersion to 4-20 wt% after dispersion, but the rate of decrease in large aggregates and increase in small aggregates is more pronounced than when no adhesive was added. I understood that. This has shown that the aggregate | assembly of a bamboo fiber becomes easy to collapse by adding an adhesive agent. Therefore, it is expected that the base with the adhesive added at the site is more susceptible to erosion than the base without the addition.

  FIG. 16 shows a result of aggregate analysis for a bamboo fiber sample dried after freezing and thawing. When no adhesive was added, aggregates having a particle size of 2.0 mm (size of 2.0 mm or more) accounted for 95 wt%, but decreased to 61 wt% due to dispersion. This amount of decrease is small compared to the case of dry bamboo fiber samples that have not undergone freezing / thawing (see FIG. 15), suggesting that freezing / thawing suppresses the collapse of bamboo fiber aggregates due to dispersion. Yes. Initially, freezing and thawing were expected to accelerate the collapse of the aggregate, but the opposite was true.

  When the adhesive was added, the aggregate having a particle size of 2.0 mm was reduced to 38 wt%, and the aggregate having a particle size of 1.0 mm or less was increased. This tendency is the same as that of the dry bamboo fiber sample of FIG. Therefore, it is predicted that the erodibility of the bamboo fiber base is increased by the addition of the adhesive.

(8) Investigation on the effects of seed fixation The effects of investigation on the germination of seeds when seeds are fixed with an adhesive will be described.

(8.1) Seed-fixed germination test method Test methods include a test group (seed-fixed test group) in which seeds are fixed with an adhesive to suppress the rotation of the seeds, and a seed can be freely rotated without fixing seeds. A test plot (seed-free test plot) that was allowed to move was prepared, and the state of seed germination in both test plots was recorded by photographing at regular intervals from a fixed position with an interval recorder. As shown in FIG. 17A, the seeds were fixed by adhering one side of the seeds to a wire mesh with an adhesive (bond for woodworking). In order to equalize the sunshine conditions, temperature conditions, and irrigation conditions in both test sections, as shown in FIG. 17 (b), an absorbent nonwoven fabric (lower layer) and absorbent cotton (upper layer) are laid in the petri dish, and the upper surface of the absorbent cotton Was divided into two, and half was designated as a seed-fixed test group (left side) and half as a seed-free test group (right half). In the seed fixation test section, as shown in FIG. 17 (a), a wire net having a seed adhered on one side was placed on absorbent cotton with the side to which the seed was adhered as the lower surface. In order to prevent seeds from moving during irrigation, irrigation into the petri dish is performed by extending a non-woven fabric for irrigation from the beaker to the lower surface of the non-woven fabric in the petri dish, as shown in FIG. This was performed by osmotic irrigation in which water was fed into the petri dish by osmotic pressure so that the absorbent cotton was kept wet all the time. As seeds to be used for the test, commercially available turf (Kentucky bluegrass) seeds were used. The number of seeds was the same in both test groups.

(8.2) Results of Seed Fixed Germination Test FIG. 18 shows changes during seed germination in the seed fixed test group and the seed free test group in the seed fixed germination test. In FIG. 19, the time change of the germination rate of each test section is shown. It is apparent from the photograph in FIG. 18 that seed germination is inhibited by seed fixation with an adhesive. As a result of the experiment, after 216 hours from the start of the experiment, the germination rate of the seed-free test group was about 70%, whereas the germination rate of the seed-fixed test group was about 10%. Therefore, the germination rate decreased by about 60% by seed fixation with an adhesive. FIG. 20 is a diagram illustrating seed movement during germination. At the time of germination, it moves so that the seed opens before buds come out from inside the seed. It is presumed that one factor is that the seed opening movement is inhibited as a factor in reducing the germination rate when fixed with an adhesive.

  The same experiment was conducted on legumes. In the case of legumes, seed rotation is not observed during germination, as in the case of gramineous plants. However, when irrigated, the legume seeds expand, and at the time of germination, the epidermis of the seeds is cleaved and germinated. During the expansion, if the seed epidermis was fixed with an adhesive, the seed epidermis was cleaved before germination, and the germs jumped out of the epidermis and dried and withered. Thus, even in the case of legumes, the germination rate is reduced by fixing the seed with an adhesive.

In the seed germination promotion method according to the present invention, the seeds are added to the cotton-like raw bamboo fibers formed by compressing and pulverizing raw bamboo shoots with a biaxial compression pulverizer, and the seeds are stirred. In a freely rotatable state, a cushion material composed of only the cotton-like raw bamboo fiber without seeds and the seeds dispersed and supported in the entangled body of the cotton-like raw bamboo fiber is produced, The seed is planted on the ground surface by laying a cushion material on the ground surface.

The method of stabilizing the slope surface layer according to the present invention comprises adding seeds of plants to cotton-like raw bamboo fibers formed by compressing and crushing raw bamboo shoots with a biaxial compression pulverizer, and stirring the seeds. However, in a freely rotatable state, a cushion material composed only of the cotton-like raw bamboo fiber and the seeds , which is dispersed and supported in the entangled body of the cotton-like raw bamboo fiber and does not contain an adhesive, is produced. ,
A cushion layer is formed by spraying the cushion material onto a natural ground surface on a slope, thereby covering the natural ground surface.

In the seed germination promotion method according to the present invention, the seeds are added to the cotton-like raw bamboo fibers formed by compressing and pulverizing raw bamboo shoots with a biaxial compression pulverizer, and the seeds are stirred. In a rotatable state, a cushion material composed only of the cotton-like raw bamboo fiber and the seeds, which is dispersed and supported in the entangled body of the cotton-like raw bamboo fiber and does not contain an adhesive and a fertilizer , is produced. The seed is planted on the ground surface by laying the cushion material on the ground surface.

The method of stabilizing the slope surface layer according to the present invention comprises adding seeds of plants to cotton-like raw bamboo fibers formed by compressing and crushing raw bamboo shoots with a biaxial compression pulverizer, and stirring the seeds. A cushioning material composed of only the cotton-like raw bamboo fiber and the seeds, which are dispersed and supported in the entangled body of the cotton-like raw bamboo fiber and are free of adhesive and fertilizer in a rotatable state. Generate
A cushion layer is formed by spraying the cushion material onto a natural ground surface on a slope, thereby covering the natural ground surface.

Claims (5)

  By adding and stirring plant seeds to cotton-like raw bamboo fibers formed by compressing and crushing raw bamboo shoots with a biaxial compression pulverizer, the seeds can be rotated and the cotton-like raw bamboo A seed germination promoting method, wherein a cushion material that is dispersed and supported in a fiber entangled body and does not contain an adhesive is generated, and the seed is planted on the ground surface by laying the cushion material on the ground surface. By adding and stirring plant seeds to cotton-like raw bamboo fibers formed by compressing and crushing raw bamboo shoots with a biaxial compression pulverizer, the seeds can be rotated and the cotton-like raw bamboo Produce a cushion material that is dispersed and supported in the fiber entanglement and does not contain adhesives.
A method for stabilizing a slope surface layer, which covers the ground surface by forming a cushion layer by spraying the cushion material onto the slope surface.   The method according to claim 2, wherein the seed of the plant is a seed of a grass family or a legume plant. The method for stabilizing a slope surface layer according to any one of claims 2 and ³ , wherein the cotton-like raw bamboo fiber has a bulk specific gravity of 0.1 to 0.3 g / cm ³ .   The method for stabilizing a slope surface layer according to any one of claims 2 to 4, wherein the cushion layer is formed on the slope surface of the slope with a thickness of 0.5 to 150 mm.